A CIRCULAR 

ON  THE 


War/r\i^  % Ventilation 

OF 

School  Houses  and  Churches 

BY 

THE  MAHONY  COMBINATION  SYSTEM, 


STEAM,  HOT  WATER  OR  WARM  AIR. 


THE  MAHONY 


WARMING  AND  VENTILATING  ESTABLISHMENT, 


MANUFACTURERS  OF 

HEATING  APPARATUS  and  CONTRACTORS  FOR  WARMING  and  VENTILATING 

PUBLIC  BUILDINGS. 


M.  MAHONY,  Proprietor.  F.  P.  SMITH,  Superintendent. 


Troy,  N.  Y. 


Digitized  by  the  Internet  Archive 
in  2017  with  funding  from 
Columbia  University  Libraries 


https://archive.org/details/circularonwarminOOmaho 


Mahonxj  Boiler. 


ggCT. 


SELF-FEEDING,  DIRECT  DRAFT  BOILER, 


FOR  STEAM  HEATING. 


§ ENTIRELY  CAST-IRON.  ^jj= 

FOR  DIMENSIONS,  POWER,  ETC.,  SEE  OTHER  SIDE. 


1=0 R f SHLE  •••  BY 


t 


SELF-CONTAINED.  REQUIRES  NO  BRICK  SETTING. 
HAS  NO  FLUES  TO  CLEAN. 


DIMENSIONS,  HEATING  POWER  »s»PRICE  LIST 

OF  THE 

MAHONY  STEAM  BOILER 

SELF-FEEDING.  WITHOUT  JACKET. 


SIZE  OF 

HEATER. 

Diameter  of 

Fire-  Box. 

Diameter 

of 

Grate. 

c . 

~ QJ 
§8 

Size  of 

Heater  Base. 

O . 

o.S  & 
~~~S 

"si 

**• 

Weight 

of 

Heater  Complete. 

Heating  Power 
in  sq.  ft.  of 
surface 

Direct  Radiation. 

Heating  Power 

in  sq.  feet  of 

surface 

Indirect  Radiation. 

Size  of 

Steam  Pipe. 

Size  of 

Return  Pipe. 

Price. 

Without 

Jacket. 

No.  0 

inches. 

10 

inches. 

9 

inches. 

51 

inches. 

17  x 20 

inches. 

33 

lbs. 

500 

sq.  ft. 

100 

sq.  ft. 

inches. 

1# 

inches. 

l 

$ 50 

No.  1 

13 

nX 

47 

22  x 27 

36 

750 

175 

IX 

iX 

75 

No.  2 

17 

uy2 

55 

26  x 31 

39 

1000 

300 

200 

2 

iX 

100 

No.  3 

21 

is  y 

56 

29  x 34 

40 

1400 

450 

300 

2 

IX 

150 

No.  4 

25 

22  x 

59 

34  x 40 

43 

1900 

650 

450 

2 y2 

2 

200 

No.  5 

31 

28y2 

68 

42  x 50 

49 

3000 

1000 

700 

3 

2^ 

250 

MAHONY  BOILER 


SELF-FEEDING,  RETURN-FLUE  BOILER, 

FOR  STEAM  HEATING.  ■; 


='  SIMPLE,  EFFICIENT,  ThEAP. 

FOR  DIMENSIONS,  HEATING  POWER^PRICES,  SEE  OTHER  SIDE. 


FOR  + SALE  f BY 


DIMENSIONS,  HEATING  POWER^PRICE  LIST 


OF  'THE 

MAHONY  STEAM  BOILER 


SELF-FEEDING,  WITH  RETURN  FLUE  JACKET,  COMPLETE, 


SIZE  OF 

HEATER. 

Diameter  of 
Fire-Box. 

Diameter 

of 

Grate. 

Diameter  of 
Jacket. 

Height  of 
Boiler. 

Size  of 

Boiler  Base. 

Height  of 
Water  Line 
from  floor. 

<V 

y 

^ js 

'5 

X 

Heating  Power 

in  sq  ft.  o< 

surface 

Direct  Radiation. 

Heating  Power 

in  sq.  ft.  of 

surface, 

Indirect  Radiation. 

Size  of 

Steam  Pipe. 

Size  of 

Return  Pipe. 

6 
i j 

£ 

inches. 

inches. 

inches. 

inches. 

inches. 

inches. 

lbs. 

sq.  ft. 

sq.  ft. 

inches. 

inches. 

No.  0 

10 

9 

17 

51 

17  x 20 

33 

550 

100 

IX 

1 

$ 70 

No.  1 

13 

11  X 

20 

47 

22  x 27 

36 

800 

175 

IX 

IX 

100 

No.  2 

17 

14X 

25 

55 

26  x 31 

39 

1100 

300 

200 

2 

IX 

130 

No.  3 

21 

18X 

30 

5G 

29  x 34 

40 

1450 

450 

300 

2 

IX 

190 

No.  4 

25 

22  % 

35 

59 

34  x 40 

43 

2000 

650 

450 

2*4 

2 

250 

No.  5 

31 

28^4 

41 

68 

42  x 50 

49 

3200 

1000 

700 

3 

2J4 

300 

SELF-CONTAINED.  VERTICAL  FLUE. 

CANNOT  BECOME  CLOGGED  WITH  SOOT. 


REQUIRES  NO  BRICK  WORK. 


Mahonu  Boiler, 


SURFACE-BURNING,  RETURN  FLUE  BOILER, 


at 

r 


■a-FiPe  Surface  Entirely  Effective.-^ 


5U 


For  Dimensions,  Seating  Power  and  Prices,  gee  0ther  gide. 


es 


fo 


FOR  -f  SALE  + BY 


tr 


DIMENSIONS,  HEATING  POWERS  PRICE  LIST 

OF  THE 

Mm  Suiface-Burnino  Steam  Boiler, 


WITH  RETURN-FLUE  JACKET,  COMPLETE. 


SIZE  OF 

HEATER. 

•_  X 

E P 

u % 
v 

q u 

jo  mswH 

X 

- Z 

■r.rz 

ill 

u '-Z 
rt  5 

** 

V 

- 

Heating  Power 
in  sq.  ft.  of 
surface 

Direct  Radiation. 

Heating  Power 
in  sq.  ft  of 
surface^ 

Indirect  Radiation. 

Size  of 

Steam  Pipe. 

Size  of 

Return  Pipe. 

Price. 

No.  0 

inches. 

10 

inches. 

9 

inches. 

17 

inches. 

4f) 

inches. 

17  x 20 

inches. 

2sy2 

lbs. 

550 

sq.  ft. 

1 00 

sq.  ft 

inches. 

IX 

inches. 

l 

$ 70 

No.  1 

13 

ny 

20 

41 

22  x 27 

31  >4 

800 

200 

IX 

iX 

100 

No.  2 

1? 

14  >4 

25 

4 sy2 

26  x 31 

34 

1100 

350 

200 

2 

1X2 

130 

No.  3 

21 

18  >4 

30 

48^4 

29  x 34 

35 

1450 

500 

300 

2 

IX 

190 

No.  4 

25 

ny2 

35 

oiy2 

34  x 40 

38  % 

2000 

700 

450 

2X 

2 

250 

No.  5 

31 

00 

41 

60 

42  x 50 

45  y2 

3200 

1000 

700 

i 

3 

2y2 

300 

Large  Fire  Surface. 

Small  Consumption  of  Fuel. 
Vertical  Flues.  Easily  Cleaned. 

Requires  no  Brick  Setting. 


SELF-FEEDING,  RETURN  FLUE  BOILER, 


Fop  Hot  ILfatep  Heating. 


IS  NOT  A SECTIONAL  BOILER 

51 

AND  CANNOT  LEAK. 


FOR  + SHLE  BY 


It 


SEE  OTHER  SXEE. 


DIMENSIONS,  HEATING  POWER^PRICE  LIST 

or"  THE 

Mahony  Hot  Water  Heater 


SELF-FEEDING,  WITH  RETURN  FLUE  JACKET,  COMPLETE. 


SIZE  OF 

HEATER. 

Diameter  of 
Fire-Box. 

Diameter 

of 

Grate. 

o 

iJ  aJ 
£ 

s«, 

Q 

O . 

o 

Si 

Size  of 

Heater  Base. 

o § O 

£ Cl  O 
btP  T 

oJ 

Weight 

< >1 

Heater  Complete. 

Heating  Power 

in  sq.  ft.  of 

surface 

Heating  Power 

in  feet  of 

One  Inch  Pipe. 

Price  with 

Return  Flue 

Jacket. 

No.  0 

inches. 

10 

inches. 

9 

inches. 

17 

inches. 

51 

inches. 

17  x 20 

inches. 

ny2 

Ibs. 

550 

sq.  ft. 

200 

lin.  ft. 

600 

$ 60 

No.  1 

13 

11^ 

20 

47 

22  x 27 

uy2 

850 

300 

900 

90 

No.  2 

17 

14J4 

25 

55 

26  x 31 

16/4 

1200 

500 

1500 

120 

No.  3 

21 

isy2 

30 

5G 

29  x 34 

17 

1700 

800 

240.0 

180 

No.  4 

25 

22  y2 

35 

59 

34  x 40 

18  }4 

2450 

1000 

3000 

240 

No.  5 

31 

28  y2 

41 

68 

42  x 50 

21 

3900 

1700 

5100 

290 

Self-Contained.  Requires  no  Brick  Setting. 

Has  no  Joints  to  become  Leaky.  Vertical  Flue. 
Cannot  become  Clogged  with  Soot. 


MAHONY  BOILER 


: IS  HOT  A SECTIONAL  BOILER 

h ..  . r 


SELF-FEEDING,  DIRECT-DRAFT  BOILER, 


Fop  Hoi1  ILfater  Healing. 


e< 

FOR  DIMENSIONS,  HEATING  POWER^PRICES,  SEE  OTHER  SIDE.  f< 


FOR  •••  SHLE  BY 


DIMENSIONS,  HEATING  POWER k^PRICE  LIST 

OF  THE 

Mahony  Hot  Water  Heater 


SELF-FEEDING,  DIRECT  DRAFT,  WITHOUT  JACKET. 


SIZE  OF 

HEATER. 

Diameter  of 
Fire-Box. 

Diameter 

of 

Grate. 

o . 

£ v 
~u  « 

•-  V 

Size  of 

Heater  Base. 

Height  of 
Return  Opening 
from  floor. 

Weight 

of 

Heater  Complete. 

Heating  Power 

in  sq.  ft.  o( 

surface 

Heating  Power 

in  feet  o/ 

One  Inch  Pipe. 

ai 

o 

£ 

No.  0 

inches. 

10 

inches. 

9 

inches. 

51 

inches. 

17  x 20 

inches. 

ny2 

lbs. 

500 

sq.  ft. 

150 

lin.  ft 

450 

$ 40 

No.  1 

13 

n# 

47 

22  x 27 

14  # 

800 

250 

750 

65 

No.  2 

17 

14  # 

__ 

00 

26  x 31 

16# 

1100 

450 

1350 

90 

No.  3 

21 

isy2 

56 

29  x 34 

17 

1600 

700 

2100 

140 

No.  4r 

25 

22  # 

59 

34  x 40 

18# 

2300 

1000 

3000 

190 

No.  5 

31 

2 sy2 

68 

42  x 50 

21 

3600 

1500 

4500 

240 

Self-Contained.  Requires  no  Brick  Setting. 

Has  no  Joints'  to  become  Leaky.  Has  no  Flues  to  Clean. 


MAHONY  BOILER 


SURFACE-BURNING,  RETURN  FLUE  BOILER, 


FOR  WATER  HEATING 


a 

:a 


■ r 


"fire  surface  entirely  effective. 


"S 


FOR  DIMENSIONS,  HEATING  POWER^PRICES,  SEE  OTHER  SIDE. 


FOR  SHLE  + BY 


U 


1 


DIMENSIONS,  HEATING  POWER^PRICE  LIST 

CF  THE 

SURFACE-BURNING 

Mahony  Hot  Water  Heater 

WITH  RETURN-FLUE  JACKET.  COMPLETE. 


SIZE  OF 

HEATER. 

o c 

B ° 

u V) 
v u 
•-  o 

Height  of 
Heater. 

Size  of 

Heater  Base. 

tc 

°5o 
r 2.  o 

'v  2 C 

Q/ 

Weight 

ol 

Heater  Complete. 

Z 

°° .. 
u- S 

i = * 

4,— 

Heating  Power 
in  feet  of 

One  Inch  Pipe. 

Price. 

inches. 

inches. 

inches. 

inches.  inches. 

inches. 

lbs. 

sq.  ft. 

lin.  ft. 

No.  0 

in 

9 

17 

40  17  x 20 

12# 

550 

200 

GOO 

$ 60 

No.  1 

13 

20 

41  22  x 27 

uy2 

850 

330 

1000 

90 

No.  2 

17 

i±y2 

25 

48 >4  20  x 31 

icy 

1200 

GOO 

1800 

120 

No.  3 

21 

18  ^ 

30 

4 Sy  29  x 34 

17 

1700 

1000 

3000 

180 

No.  4 

25 

22  y2 

35 

oiy2  34  x 40 

is  y 

2450 

1200 

3G00 

240 

No.  5 

31 

2sy 

41 

00  42  x 50 

21 

3900 

2000 

6000 

a9° 

Small  Water  Space.  Rapid  Circulation. 

Large  Fire  Surface. 

Economy  of  Fuel.  Easily  Cleaned. 


PREFACE. 


The  principal  purpose  of  this  book  is  to  call  the  attention  of  Architects,  Boards  of  Education  and 
Officers  of  Churches  to  the  apparatus  we  manufacture,  and  the  systems  we  use  for  Warming  and  Ventilating 
School  Houses  and  Churches. 

Our  claims  for  consideration  are  simply  these  : We  manufacture  the  apparatus  necessary  for  successfully 
introducing  our  systems,  and  we  guarantee  that  all  contracts  taken  by  us  shall  be  filled  to  the  satisfaction  of 
the  Architect  or  other  person  or  persons  with  whom  the  contract  is  made. 

All  responsibility  for  the  success  of  our  work  and  all  risk  of  failure,  or  expense  entailed  by  reason  of 
failure  of  our  system  to  work  as  represented,  is,  by  express  terms  of  contract,  assumed  by  us.  We  will 
undertake  the  warming  and  ventilation  of  all  classes  of  school  houses  or  churches,  by  either  steam,  hot  zvater, 
or  warm  air,  or  by  combination  of  steam  and  warm  air,  or  hot  water  and  warm  air. 

It  does  not  make  the  slightest  difference  to  us,  in  the  matter  of  profit,  which  system  we  use  to  secure  the 
heat,  on  which  depends  the  ventilation. 

We  are  at  liberty,  therefore,  to  correctly  state  the  merits  and  demerits  of  each  system  without  fear  of 
prejudicing  our  own  interests.  Whatever  system  may  be  used  for  heating,  there  must  be  a very  large  volume 
of  air  warmed  for  ventilating  purposes,  and,  if  it  is  true,  as  claimed  by  many,  that  there  is  difficulty  in  heating 
certain  rooms  of  a building  in  windy  weather  with  furnaces,  it  is  no  less  true  that  there  is  just  as  great 
practical  difficulty  experienced  in  7 >entilating  a school  house  or  church  where  steam  or  hot  water  are  used. 
The  difficulties  are  exaggerated  in  both  cases  and  can  be  readily  overcome  by  those  who  understand  the 
cause  of  the  trouble. 

It  is  because  there  are  difficulties  met  with  in  the  introduction  of  every  system,  whether  it  be  steam,  hot 
water  or  warm  air,  that  the  work  should  never  be  entrusted  to  persons  who  have  neither  the  education 
necessary  to  enable  them  to  make  the  requisite  calculations  for  planning  a system  of  ventilation  nor  the 
experience  on  which  alone  good  judgment  can  be  based. 

We  make  a specialty  of  school  house  ventilation,  and  whether  we  understand  our  work  or  not,  we  are 
willing  to  make  a contract  to  obtain  certain  specified  results  which  very  few  firms  care  to  sign.  If  we  did 
not  know  from  past  experience  that  we  were  working  on  correct  principles,  we  could  not  afford  to  assume 
the  responsibility  we  do  when  we  make  our  contracts. 

We  desire  to  correspond  with  those  interested  in  warming  and  ventilating  school  houses  and  churches. 

We  draw  plans  and  specifications  for  heating  and  ventilating  buildings,  and  will  furnish  the  same  for  a 
reasonable  consideration.  No  charge  will  be  made  for  the  plans  furnished  where  we  are  given  the  contract 
for  performing  the  work. 

When  the  erection  of  new  buildings  or  the  introduction  of  new  heating  and  ventilating  apparatus  is 
contemplated,  we  shall  be  glad  to  call,  upon  request,  to  consult  with  those  in  charge,  concerning  the  heating 
and  ventilation. 

Respectfully, 


THE  MAHONY  HEATING  AND  VENTILATING  ESTABLISHMENT. 


THE  MAKING  OF  CONTRACTS 


for  warming  and  ventilating  School-houses  and  Churches,  is  too  frequently  delayed  until  the  contracts  for 
erecting  the  building  have  been  let,  when  it  is  often  too  late  to  introduce  any  system  in  the  best  manner, 
without  alterations  in  plans  and  consequent  annoyance. 

The  contract  for  the  heating  and  ventilation  should  be  let  just  as  soon  as  the  general  plan  and  size  of  the 
building  have  been  decided  upon,  and  the  contractor  for  the  work  should  prepare  the  plans  and  specifications 
for  the  construction  of  the  necessary  chimneys,  flues,  etc.,  and  these  should  be  included  in  and  become  a part 
of  the  regular  plans  and  specifications  furnished  by  the  architect. 

How  to  secure  (food  results. — Most  committees  take  the  course  least  likely  to  secure  satisfactory 
results.  After  the  building  is  otherwise  completed  it  is  the  frequent,  if  not  general  practice,  to  advertise  for 
bids  for  the  heating  and  ventilation,  with  the  understanding  that  the  lowest  bidder  shall  receive  the  con- 
tract. Each  one  is  generally  permitted  to  furnish  what  he  pleases,  the  only  question  the  committee  are  inter- 
ested in  being,  “ who  will  do  the  job  the  cheapest.” 

Thus,  stove  dealers,  tinsmiths,  and  plumbers  are  often  permitted  to  compete  for  the  contracts,  and  their 
bids  are  considered,  though  they  may  not  understand  the  simplest  principles  of  ventilation,  or  be  in  any  way 
fitted  to  do  work  requiring  education,  skill  and  good  judgment. 

Since  the  lowest  bidder  is  to  get  the  contract,  it  is  natural  that  each  one  should  cut  out  every  possible 
item  that  can  be  omitted. 

The  acceptance  of  the  lowest  bid  under  such  circumstances  means  that  the  cheapest  man,  the  man  with 
the  least  knowledge  or  experience,  is  entrusted  with  the  duty  of  providing  for  the  health  and  comfort  of  hun- 
dreds of  persons,  and  the  committee,  instead  of  securing  a system,  with  all  the  good  points  in  it,  have  accept- 
ed that  in  which  as  much  as  possible  has  been  left  out.  Surely,  it  is  not  to  be  wondered  at,  that  there  are 
thousands  of  poorly  heated  school  houses,  and  almost  none  which  are  ventilated. 

The  proper  way  to  proceed , is  to  have  some  competent  engineer  or  architect  specify  the  results 
to  be  obtained.  Then  let  those  who  desire  to  submit  proposals  for  doing  the  work,  specify  the  exact  apparatus 
they  propose  to  furnish  and  explain  the  system  they  propose  to  use. 

Let  it  be  understood  that  the  contractor  must  furnish  apparatus  which  will  heat  the  building  to  70°  F.,  in 
any  weather,  and  at  the  same  time,  introduce  from  out-doors  and  warm  a volume  of  air  equal  to  the  cubic 
contents  of  the  building,  as  often  as  every  twenty  minutes,  without  causing  unpleasant  draughts  in  the  rooms, 
and  also  expel  through  the  ventilating  shaft  an  amount  of  air  equal  to  that  admitted. 

Let  it  be  agreed,  also,  that  the  architect  shall  thoroughly  test  the  working  of  apparatus  and  system,  and 
that  it  is  upon  his  certificate  that  payment  shall  be  made  for  the  apparatus  furnished.  Having  received  the 
proposals  and  heard  the  explanations  of  the  several  bidders,  select  that  system  which  appears  to  possess  the 
greatest  merits,  rather  than  the  cheapest  one,  and  the  result  will  prove  the  wisdom  of  the  choice. 

When  a building  is  already  erected,  and  it  is  desired  to  introduce  new  heating  and  ventilating  apparatus, 
we  will  make  contract  direct  with  the  School  Board  to  secure  the  results  specified  above.  While  in  all 
buildings  we  may  not  be  able  to  introduce  our  complete  system,  we  can  always  secure  fair  results. 


6 


VENTI  LATION. 


We  wish  to  state  right  here,  that  what  we  have  to  write  upon  this  subject  is  not  original.  All  the  princi- 
ples set  forth  have  been  written  about  and  accepted  for  many  years.  We  have  not  discovered  anything  new 
though  we  have  our  own  methods  of  applying  what  is  known  and  accepted  as  correct  to  actual  practice. 

What  we  mean  in  practice  by  a method  of  good  ventilation,  is  that  system  which  will,  without  complicated 
apparatus,  maintain  within  a building  a certain  standard  of  purity  of  the  air,  by  withdrawing  that  which  is 
vitiated,  and  supplying  its  place  with  pure  fresh  air,  without  causing  unpleasant  draughts  through  the 

rooms. 

We  do  not  contend,  as  many  do,  that  there  is  and  can  be  only  one  correct  system,  and  then  modestly 
claim  we  are  the  only  ones  who  can  or  do  use  it. 

There  are  two  general  systems,  based  upon  essentially  different  principles,  known  as  the  Plenum  and 
Vacuum  methods. 

The  principle  upon  which  the  first  is  based  is  : that  if  a given  volume  of  air  be  forced  into  a room, 
under  pressure,  an  equal  amount  will  be  forced  out. 

The  principle  of  the  second  is  : that  if  a certain  volume  of  air  be  exhausted  from  a room  an  equal 
amount  of  fresh  air  will  come  in  to  replace  it. 

“Natural  Systems.” 

Both  the  Plenum  and  the  Vacuum  methods  are  based  upon  natural  laws.  Yet  neither  can  properly  be 
called  “ natural  ” systems. 

The  steam  engine  is  based  upon  natural  principles,  yet  its  work  can  hardly  be  said  to  be  performed  by 
natural  means. 

To  ventilate  a school  house  or  church,  it  is  necessary  to  lift  an  immense  weight  of  air  in  a single  day  ; in 
other  words,  work  must  be  done  and  force  expended,  and  this  work  must  be  done  and  force  obtained  by 
artificial , and  not  natural  methods. 

There  are  numerous  causes  which  render  the  Plenum  system  difficult  of  application  and  uncertain  in  its 
results,  and  we,  therefore,  confine  ourselves  to  the  consideration  of  the  principles  of  the  Vacuum  or  exhaust 
method,  on  which  our  system  is  based. 

The  requirements  of  this  method  are  : 

ist.  A vertical  shaft  or  flue,  known  as  the  ventilation  shaft,  to  which  each  room  in  the  building  is  con- 
nected by  suitable  flues  or  ducts  of  proper  size  and  shape. 

2nd.  A means  of  creating  a vacuum,  or  exhaust  draft,  in  the  vertical  shaft. 

3rd.  Suitable  inlets  for  the  pure  air. 

4th.  A means  of  warming  the  fresh  air. 

5th.  The  proper  valves,  dampers,  etc.,  for  regulating  and  controlling  the  system.  These  requirements 
just  mentioned  are  agreed  upon  by  all  writers  as  essential  to  a good  system  of  ventilation,  but  when  the  ques- 
tion of  how  to  put  the  system  into  practical  operation  in  the  various  classes  of  buildings,  differing  as  they  do 
in  size,  material,  exposure,  location  and  uses,  is  considered,  authorities  differ,  and  the  trouble  begins. 

It  is  very  generally  admitted  that  the  simplest  force  for  moving  the  large  volume  of  air  necessary  is  grav- 
ity. The  air  in  the  ventilation  shaft  is  rendered  specifically  lighter  than  that  in  the  building  by  heating  it, 
and  is  forced  upward  by  the  heavier  air  from  the  rooms  descending  and  displacing  it. 


But  now  comes  the  trouble.  If  we  ask  : “Where  shall  the  warm,  fresh  air  be  admitted  to  the  rooms  ?” 
one  replies,  “at  the  ceiling;”  another,  “at  the  floor.” 

“ At  what  point  should  the  foul  air  be  withdrawn  ? "again  one  says,  “ From  the  floor,  for  carbonic  acid 
gas  and  the  exhalations  from  the  body,  are  one-third  heavier  than  air  and  settle  to  the  floor.”  Another, 
disputes  this,  and  says,  “from  the  ceiling,  for  the  breath,  being  warmer  than  the  air  of  the  room,  rises.” 

Do  we  venture  to  inquire,  “ What  is  the  best  method  of  heating,  ” we  find  no  lack  of  answers.  The 
maker  of  steam  heating  apparatus  assures  us  that  “Furnaces  burn  the  air,”  “destroy  the  oxygen,”  “leak 
gas,”  “ give  a dry  heat,”  “ will  not  work  in  windy  weather,”  and  much  more  of  the  same  sort. 

The  furnace  men  first  have  it  out  among  themselves,  over  the  question  of  material.  The  advocate  of 
“ wrought-iron  ” or,  “steel-plate,”  gravely  informs  us  on  “eminent  French  authority,”  that  “cast-iron  is 
porous  and  filled  with  minute  sand  holes,  and  when  red-hot,  permits  the  free  passage  of  carbonic  acid  and 
other  poisonous  gases  through  them.  The  “ cast-iron  ” man  retorts  on  equally  good  authority,  that  if  “air 
be  brought  into  contact  with  red-hot  wrought-iron,  carbonic  oxide,  more  deadly  than  carbonic  acid,  is 
generated.” 

Then  both  unite  against  their  common  enemy,  steam,  and  proceed  to  terrify  us  with  statistics  of  boiler- 
explosions.  They  say,  “ steam  heating  is  very  expensive  to  introduce,  to  keep  in  repair,  and  for  fuel,” 
“ steam  heating  is  dangerous  to  health,  because  it  secures  no  ventilation.”  “Radiant  heat  will  not  warm  a 
room  evenly,”  etc.,  etc. 

Our  criticism  of  all  this  is  : that  while  each  may  understand  his  own  business,  he  knows  very  little  about 
the  rival  system  which  he  criticises  so  freely.  As  an  instance  of  this,  we  quote  from  the  catalogue  of  a quite 
prominent  “Warming  and  Ventilating  Company,”  who  manufacture  Hot-Air  Furnaces,  or  “ Air- Warmers,” 
where  this  statement  appears  from  the  pen  of  a college  “professor”:  “ Now  heat  may  manifest  itself  in  two 
“ ways,  viz  : as  temperature  and  as  expansion  ; * * * * if  a building  is  warmed  by  steam  three- 

“ fifths  of  the  force  generated  by  the  burning  fuel  is  consumed  in  the  form  of  mechanical  motion.  The 
“temperature  of  the  steam  in  the  boiler  may  be  400°  or  500°  F.,  but  the  pipes  never  indicate  over  2120.  I have 
“never  found  it  above  190°  F.  ” The  utter  absurdity  of  this,  is  at  once  apparent,  when  it  is  understood  that 
a temperature  of  400°  to  500°  F.,  can  only  be  obtained  with  a corresponding  pressure  of  from  290  lbs.  to  350  lbs. 
on  every  square  inch  of  interior  surface  of  boiler,  pipes  and  radiators  ; while  steam  heating  is  usually  accom- 
plished with  a pressure  of  from  5 lbs.  to  10  lbs.  per  square  inch  ; the  “safety-valve”  being  generally  set  to 
“blow-off  ” at  about  15  lbs.  pressure,  or  a temperature  of  not  over  230°  F. 

There  are  altogether  too  many  “hobbies”  ridden  in  this  field  of  warming  and  ventilation.  Too  many 
get  astride  some  one  fact  and  ride  it  to  death,  the  while  forgetting  or  overlooking  other  equally  important 
conditions  which  tend  to  offset  or  neutralize  those  they  are  concentrating  the  force  of  their  intellect  upon. 

Unbalanced,  lop-sided,  “systems”  are  met  with  everywhere.  Ventilating  flues  are  put  in  buildings  and 
expected  to  exhaust  the  air  though  no  heat  be  applied,  and  people  wonder  why  the  air  comes  down  instead  of 
rising.  Or  openings  are  made  at  the  ceiling  and  surprise  is  expressed  because  the  rooms  cannot  be  warmed. 
Others  attempt  to  “ventilate”  a room  which  is  heated  by  direct  steam  radiation,  and  wonder  why  the  floors 
are  so  cold.  All  these  failures  are  the  result  of  someone’s  “ hobby-riding.”  The  numerous  “systems”  which 
work  with  reverse  action  prove  the  truth  of  this. 

We  do  not  consider  that  it  makes  any  practical  difference  whether  the  breath  rises  or  falls,  as  to  the  point 
at  which  we  should  exhaust  the  vitiated  air  from  a room.  We  know  that  the  fresh  warm  air  which  we  admit 
to  the  room,  rises  to  the  ceiling,  and  that  if  we  were  to  make  an  opening  there  our  purest  air  would  at  once 
escape,  and  there  would  be  no  ventilation.  Even  if  the  object  be  to  cool  off  a room,  it  ought  not  to  be  by 


8 


opening  registers  at  the  ceiling,  but  by  shutting  off  the  warm  air  and  admitting  the  cool  air,  as  provided  for 
in  our  system  of  continuous  ventilation. 

Air  moves,  like  any  other  substance,  in  obedience  to  force,  and  if  we  exhaust  the  air  from  the  lower  part 
of  a room,  as  we  do  in  practice  by  the  force  of  gravity,  the  pure  warm  air  will  descend  to  replace  it. 

The  question  of  the  material — whether  wrought  or  cast-iron — of  which  a furnace  should  be  constructed 
is  of  trifling  importance.  The  principal  causes  of  leakage  of  gas  from  furnaces,  is  the  small  extent  of  heat- 
ing surface  and  consequent  high  temperature  to  which  they  are  raised,  and  the  neglect  of  the  fresh  air  supply. 
In  the  furnace  there  are  two  drafts,  viz  : one  up  the  chimney,  the  other  up  the  warm  air  flues.  The  inner 
flue  is  supplied  through  the  grate.  The  outer  flue  is  intended  to  be  supplied  through  the  fresh  air  duct, 
and  when  that  is  closed,  as  it  so  often  is,  there  is  a tendency  to  fill  the  vacuum  from  the  fire  chamber.  The 
principle  is  precisely  the  same  as  that  by  which  we  draw  the  foul  air  from  a room  in  our  system  of  ventilation. 

A furnace  should  never,  and  if  one  of  proper  size  be  used,  need  never,  become  red-hot. 

We  have  already  stated  that  it  made  no  difference  to  us  in  the  matter  of  profit,  which  system  we 
employed  for  heating  the  building  and  the  air  for  ventilation.  We  now  state  that  it  makes  little  or  no 
difference  which  system  we  use  to  secure  the  desired  results. 

It  must  be  borne  in  mind  that  our  work  is  to  both  heat  and  ventilate  the  building  at  the  same  time.  The 
same  heat  which  warms  the  building  will  not  also  perform  the  wofk  of  ventilating  it. 

Another  thing  : We  must  not  secure  ventilation  at  the  expense  of  warmth  and  comfort,  nor  must  we,  as 
is  now  generally  done,  secure  the  warmth  by  sacrificing  the  ventilation  and  health. 

We  therefore  need  apparatus  which  will  provide  heat,  during  cold  weather,  for  three  distinct  purposes, 
viz.:  Heat  to  warm  the  building  ; heat  to  warm  the  fresh  air  for  ventilating  purposes,  and  heat  to  create  the 
exhaust  draft  in  ventilation  shaft.  In  warm  weather  we  need  heat  for  the  latter  purpose  only 

The  Source  of  Heat. 

We  manufacture  Warm-Air  Furnaces,  Hot-Water  Heaters,  Steam  Boilers,  Combination  Warm-Air  and 
Steam  Apparatus,  and  Combination  Warm-Air  and  Hot-Water  Heaters.  We  can  therefore  take  our  choice  of 
apparatus  for  securing  heat  for  the  purposes  named  above. 

For  heating  the  rooms  quickly  and  with  certainty  in  all  weather,  we  can  get  nothing  which  does  the  work 
better  than  steam.  , 

For  warming  the  very  large  volume  of  air  necessary  for  ventilation,  and  for  heating  the  ventilating  flue 
we  can  get  nothing  which  will  do  the  work  better,  or  with  so  little  trouble  as  our  Warm-Air  Furnace. 

When  the  fresh  air  for  ventilation  is  warmed  by  steam  or  hot-water,  it  is  done  by  the  system  of  “ indirect 
radiation,”  or,  as  we  explain  in  the  article  on  heat,  by  convection.  These  indirect  radiators  are  radiators 
which  are  placed  within  fresh  air  ducts  and  heat  the  air  as  it  passes  over  their  surface.  The  apparatus 
necessary  for  perfect  control  and  regulation  of  this  system  is  quite  complicated  and  much  more  likely  to  get 
out  of  order  than  the  “ air-warmer,”  or  furnace  which  does  the  same  work.  Therefore,  taking  into  consid- 
eration all  the  advantages  and  disadvantages  of  each  system,  including  the  cost  of  introducing  and  main- 
taining the  apparatus,  we  unhesitatingly  declare  in  favor  of  the  Warm-Air  Furnace  over  steam  for  all  such 
buildings  as  school  houses  and  churches  where  a large  supply  of  pure  air  is  as  necessary  as  warmth. 

The  best  possible  system  is  undoubtedly  the  one  which  includes  the  advantage  of  both,  and  leaves  out  the 
difficulties,  if  that  were  possible.  We  do  not  claim  to  have  reached  perfection  yet,  but  we  have  made  a long 
step  towards  it  in  our 


Combination  Apparatus. 

With  this  we  heat  the  room  by  direct  radiation  with  steam  or  hot  water,  and  warm  the  air,  for  ven- 
tdating, with  the  Air- Warmer.  We  thereby  retain  the  advantage  we  possessed  with  steam,  of  heating  distant 
rooms  with  certainty  in  any  weather,  and  the  advantage  of  the  furnace  of  being  able  to  warm  the  pure  air 
without  complicated  apparatus. 

As  before  stated,  we  employ  either  system  which  seems  best  suited  to  the  building  we  desire  to  heat 
and  ventilate,  guaranteeing  and  becoming  responsible  for  equally  good  results  with  either , provided  people  are 
willing  to  pay  for  the  necessary  apparatus. 

Of  the  Necessity  of  Ventilation, 

we  say  but  little,  for  people  are  already  becoming  convinced  of  the  absolute  necessity  of  providing  pure 
air  in  the  school  house  if  their  children  are  to  have  strong  bodies  and  active  minds.  Boards  of  Health, 
State  Boards  of  Education  and  State  Legislatures  are  all  urging  and  compelling  the  introduction  of 
apparatus  which  will  permit  a child  to  secure  an  education  without  its  health  being  ruined.  People  do  not  so 
much  need  to  be  told  what  they  want  as  how  to  get  it. 


EXPLANATION  OF  PLATES. 

For  illustrating  as  clearly  as  possible  the  principles  on  which  our  system  is  founded,  we  have  prepared  a 
series  of  plates.  The  difficulty  of  showing  the  movement,  under  varied  conditions,  of  a substance 
like  air,  which  is  nearly  invisible,  will  be  recognized  by  the  reader,  but  a little  study  will,  we  think,  make  clear 
what  we  wish  to  show.  We  represent  the  heat  and  warm  air  by  the  red  tint,  the  cold  and  foul  air  by  the 
blue  tint.  The  arrows  indicate  the  directions  of  the  currents. 

Plate  “A”  represents  the  condition  of  the  air  in  a room  heated  exclusively  by  an  open  fire-place.  It  will 
be  seen  at  a glance,  what  our  fathers  learned  by  long  experience,  that  the  room  is  very  unequally  warmed. 
The  heating  is  wholly  by  direct  radiation,  and  the  fire-place  is  at  one  side  of  the  room.  A large  amount  of 
air  is  going  up  the  chimney  and  its  place  must  be  and  is  filled  with  cold  air  from  out-doors,  thus  causing 
currents  of  cold  air  across  the  floor. 

Plate  “B”  shows  the  same  room,  but  the  fire-place  is  now  used  only  to  exhaust  the  air  from  the  room 
while  the  supply  of  fresh  air  to  replace  that  withdrawn,  is  no  longer  coming  in  cold  through  cracks  and 
crevices,  but  warm  from  the  furnace.  We  now  have  a large  volume  of  warm  air  which  is  evenly  distributed 
in  all  parts  of  the  room.  This  system  is  correct  in  principle  and  admirable  in  practice  except  for  the 
inconvenience  of  caring  for  a separate  fire  in  each  room. 

Plate  “ C ” shows  the  effect  of  an  opening  near  the  ceiling  on  the  ventilation  of  a room,  and  if  the 
building  is  warmed  by  a furnace,  on  the  heating  also.  Our  pure  air  is  coming  in  warm  and  rises  to  the  ceiling 
whence  it  escapes  without  having  changed  the  air  in  the  room  at  all.  It  will  be  found  impossible  to  heat 
the  room  with  warm  air  if  the  register  be  open,  and  it  will  therefore  be  closed,  and  there  is  no  longer  an 
outlet  for  the  air.  This  is  the  present  condition  of  very  many  buildings  with  respect  to  ventilation. 

Plate  “ D ” shows  the  same  room  with  opening  to  vent  flue  at  floor.  As  our  warm  and  pure  air  can  no 
longer  escape  until  it  has  reached  the  lowest  part  of  the  room,  the  ventilating  register  may  be  always  open 
and  the  room  will  be  evenly  warmed  and  thoroughly  ventilated.  This  method  is  correct  and  one  we 
frequently  use  in  buildings  already  constructed.  The  only  possible  criticism  of  this  plan  is  that  the  air  is  all 
withdrawn  at  one  large  opening  and  too  strong  drafts  may  be  created. 


10 


Plate  “ E ” is  used  to  illustrate  several  systems.  It  shows,  first,  our  method  of  warming  and  ventilating 
by  warm  air  from  the  furnace.  It  will  be  noticed  that  the  warm  air  is  admitted  at  the  ceiling  instead  of  the 
floor.  This  accords  with  the  true  principle,  though  if  the  air  be  admitted  at  the  floor  it  immediately  ascends 
to  the  ceiling.  By  having  the  warm  air  admitted  at  the  ceiling  a very  important  difficulty,  that  of  sending 
warm  air  to  distant  rooms,  is  overcome,  for  not  only  is  the  elevation  thereby  increased,  but  the  wind  can 
no  longer  force  the  warm  air  back  to  the  furnace. 

The  plate  also  shows  the  system  of  heating  the  room  with  steam  or  hot  water  by  direct  radiation  and 
ventilating  it  by  fresh  air  warmed  by  the  indirect  radiators  or  a furnace.  The  same  plate  also  serves  to 
illustrate  the  combination  system  by  which  with  the  same  apparatus  we  generate  the  steam  or  heat  the  water 
for  heating  the  room  and  warm  the  air  for  ventilating  it.  This  system  is  correct  in  principle  and  has  many 
advantages  in  practice. 

Plate  “ F ” shows  our  system  complete.  l'he  warm  air  for  heating  and  ventilating  the  room  is  admitted 
through  the  register  at  ceiling.  The  foul  air  is  withdrawn  through  numerous  small  registers  instead  of  one 
large  one,  and  carried  under  the  floor  to  ventilation  shaft.  By  this  means  an  almost  uniform  temperature  is 
secured  in  all  parts  of  the  room.  By  the  use  of  furring  strips  across  the  floor-joists,  as  shown  in  the  plate, 
the  free  movement  of  air  is  permitted  in  all  directions,  under  the  floor. 

Plate  “G”  shows  a section  of  the  building  for  the  purpose  of  illustrating  our 

System  of  Continuous  Ventilation. 

\\  hen  Warm-Air  Furnaces  are  used,  the  warm  air  for  heating  is  also  the  fresh  air  for  ventilating. 
If  the  room  becomes  too  warm,  the  register  is  closed  to  shut  off  the  heat,  and  that  shuts  off  the  fresh  air  also. 
Our  system  is  so  arranged  that  the  air  supply  cannot  be  shut  off,  though  it  can  be  introduced  either  warm  or 
cool  as  desired.  Referring  to  the  plate:  “A”  is  the  warm  air  chamber  or  furnace  room  ; “ B,”  “B  ” are  the 
outlets  for  cool  air  from  the  air-ducts;  “ D,”  “ D,”  “ C,”  “C”  are  outlets  for  the  warm  air  into  the  flues 
leading  to  the  several  rooms. 

The  temperature  of  the  room  is  controlled  by  opening  or  closing  the  dampers  at  “ C,”  “ C,”  by  means  of 
the  lever  “ S,”  which  is  placed  in  a convenient  location  in  each  room. 

The  damper  at  left  of  warm-air  chamber  “A”  is  shown  closed  so  that  only  cool  air  is  admitted  to  the 
flue,  while  that  on  the  right  is  partially  opened,  and  both  warm  and  cool  air  are  obtained  in  the  proportion 
ddsired.  It  will  be  observed  that  if  the  heat  be  entirely  shut  off  from  the  school  rooms  the  flues  are  still 
open  to  the  air-duct  “ D,”  and  the  fresh  cool  air  is  drawn  in  to  replace  that  exhausted  by  the  ventilation 
shaft. 

Summer  Ventilation 

is  frequently  neglected  even  where  some  attempt  is  made  to  supply  fresh  air  when  the  furnaces  are  in  use. 
Our  system  provides  for  the  admission  of  cool  air  during  the  warm  weather  without  the  necessity  of  opening 
windows. 

The  Patent  Automatic  Air-Valve 

shown  at  “ E,”  is  a very  important  part  of  the  apparatus  comprising  our  system.  Simple  as  it  is,  it  perfectly 
controls  the  supply  of  air  required  for  ventilation  and  warming.  Its  great  value  is  due  to  the  fact  that  it 
takes  out  of  the  hands  of  the  janitor  the  work  requiring  the  most  intelligence  and  best  judgment,  and  does 
automatically  what  the  janitor  frequently  fails  to  do  at  all,  and  never  can  do  as  well.  By  the  use  of  this  air- 
valve,  the  volume  of  air  admitted  is  always  the  same  whether  it  be  windy  or  calm  weather.  The  importance 
of  the  air  supply  is  fully  shown  under  the  head  of  “Convection.”  This  device  is  fully  covered  by  letters 
patent. 


11 


Plate  “ H,”  is  an  isometric  drawing  of  basement  plan  of  school  house,  showing  the  manner  in  which  we 
■use  the  foul  air  from  the  building  to  serve  a very  useful  purpose  before  it  is  finally  expelled  by  the  ventilation 
shaft.  The  arrows,  if  carefully  followed  from  the  air-duct  “h”  to  ventilation  shaft  E,  will  indicate  the 
■course  travelled  by  the  foul  air.  Entering  at  the  air-duct,  the  air  passes  to  the  warm-air  chamber  “A,”  from 
which  it  is  distributed  through  the  building,  by  the  flues  “a,”  “a,”  “ b,”  “b.”  Having  passed  through  the 
rooms  it  is  withdrawn  through  the  ventilating  registers  and  brought  back  to  the  basement  into  the  foul  air 
gathering  room,  “ B.” 

From  the  foul  air  room  “B”  the  air  passes  through  the  openings  “e,”  “e,”  beneath  the  seats  of  the  privies, 
and  there  evaporates  all  moisture  and  carries  off  all  odors. 

This  Dry  Closet  System 

has  been  introduced  into  many  school  houses  by  the  “ Ruttan-Smead  Warming  and  Ventilating  Company,” 
and  is  a success.  We  have  simplified  and  improved  upon  their  methods  as  they  improved  upon  the  methods 
of  others,  and  we  claim  for  our  system  great  advantage  over  any  yet  practically  introduced  for  water-closets 
or  privies. 

The  Smoke  Flue 

is  usually  built  within  the  ventilation  shaft,  and  when  the  furnaces  are  in  operation,  generally  heats  the  shaft 
sufficiently  without  the  use  of  the  small  furnace  which  is  set  at  the  base  of  ventilation  shaft  for  use  in 
summer,  or  when  the  heat  from  the  chimney  is  insufficient  to  secure  a strong  circulation  of  fresh  air. 

Plate  “ I ” is  an  isometric  drawing  of  our  complete  system  as  introduced  into  the  new  school  house 
erected  in  District  No.  4,  Johnstown,  New  York. 

The  drawing  shows  one  end  of  the  building  cut  away  to  give  a view  of  the  automatic  air  valve  ; the 
fresh  air  duct  beneath  basement  floor  ; the  warm  air  chamber  in  which  furnaces  are  to  be  placed  ; the  openings 
for  warm  and  cool  air  to  flues  leading  to  school-rooms  ; the  foul  air  flues  to  dry  closets  ; the  small  furnace  in 
foul  air  room  and  the  ventilation  shaft  and  smoke  flue. 

By  following  the  course  travelled  by  the  air  as  indicated  in  the  cut  by  the  arrows,  it  will  be  seen  that  it 
enters  the  building  through  the  automatic  air  valve,  which  controls  the  volume  admitted,  passes  thence  to  the 
warm  air  chamber  where  it  is  heated  and  sent  up  to  the  several  rooms  on  first  and  second  floors,  where  it 
does  its  work  of  warming  and  ventilating. 

After  serving  this  purpose,  the  process  of  ventilation  is  continued  by  withdrawing  the  air  through  the 
numerous  small  registers  placed  about  the  room  in  the  base  board,  from  whence  it  passes  under  the  floor  to 
the  ventilation  flues  which  carry  the  air  back  to  the  basement,  where,  as  previously  explained,  it  is  used  to 
evaporate  the  deposits  in  the  closets  before  it  finally  passes  to  the  ventilating  shaft  and  thence  out  of  the 
building. 

We  thus  secure  Dy  this  means  a constant  current  of  fresh  air  through  the  building,  and  this  action  is 
positive  and  reliable.  If  the  flues  be  of  proper  size  and  the  system  properly  introduced,  there  will  always  be 
the  same  positive  currents  and  certain  results  in  any  weather  if  the  ventilating  shaft  is  heated. 


12 


THE  MAHONY  “AIR-WARMER”  OR  FURNACE, 

For  school  house  and  church  work,  is  constructed  with  a view  of  bringing  the  largest  possible  volume  of  air 
in  contact  with  the  furnace. 

In  constructing  a furnace,  the  following  points  must  not  be  overlooked  : 

ist.  The  purpose  of  the  furnace  is  to  warm  air. 

2nd.  Air  can  be  warmed  by  contact  only. 

3rd.  The  volume  of  air  which  can  be  warmed,  at  the  same  instant,  depends  upon  the  extent  of  the  warm 
surface  with  which  it  can  be  brought  in  contact. 

4th.  There  is  no  practical  gain  in  heating  power , while  there  is  a great  loss  in  the  quality  of  the  airy 
from  having  a very  high  temperature  in  the  furnace. 

Dulong  records  the  results  of  his  experiments  as  follows  : “ With  radiation  the  higher  the  temperature 
“of  the  heating  surface  the  greater  the  proportion  of  the  heat  given  out  for  each  degree’s  difference  between 
“the  heated  body  and  the  surrounding  air.” 

“ But  with  convection  the  yield  per  degrees  difference  is  for  all  practical  purposes,  irrespective  of  the 
“ absolute  temperature  of  the  heated  body,  or  of  the  difference  of  temperature  of  the  heated  body  and  the  air 
“ in  contact  with  it.” 

“With  a radiant  body  at  a clear  red  heat  of  1,015°  C,  the  amount  of  heat  transmitted  per  meter  per  hour 
“is  about  300  times  that  transmitted  at  ioo°  C,  and  at  a white  heat  of  1,415°  C it  rises  to  4,604  times  that 
“amount.” 

“ With  convection,  however,  the  difference  in  loss  of  heat  per  degree  is  comparatively  slight.  Supposing 
“that  with  the  heated  body  at  o°  C,  and  the  air  at  15°  C,  the  loss  by  contact  or  by  radiation  were  1,  at  250°  it 
“ would  be  by  contact  only  1.9,  while  by  radiation  it  would  be  as  high  as  3 ; at  310°,  510°,  1,015°  and  I>415°> 
“the  loss  by  contact  would  be  2,  2.3,  2.7  and  2.9  respectively,  while  by  radiation  it  would  be  4,  13,  300  and 
“4,604  times  greater  respectively  than  at  0° 

5th.  For  a given  amount  of  fuel  the  same  amount  of  heat  will  be  generated  by  combustion,  whether  the 
combustion  be  slow  or  rapid.  The  value  of  a furnace  will  therefore  depend  upon  the  amount  of  heat  saved 
and  imparted  to  the  air  by  it  compared  with  that  lost  through  the  smoke  flue,  and  the  amount  of  heat  saved 
will  depend  upon  the  extent  of  heating  surface,  and  the  rapidity  of  combustion. 

•Though  a furnace  may  have  considerable  extent  of  surface,  it  may  still  be  so  constructed  so  that  the  loss 
of  heat  will  be  great  from  too  rapid  combustion. 

Consideration  of  these  facts  proves  conclusively  that  it  is  not  the  furnace,  which  by  its  “superior 
construction,  concentrates  the  heat,”  nor  the  one  in  which  an  “intense  heat  can  be  quickly  obtained,”  but 
that  which  spreads  the  heat  most  evenly  over  the  largest  extent  of  surface,  which  is  the  superior  one. 
In  other  words,  great  extent  of  heating  suface  with  slow  combustion,  are  the  points  to  be  sought  for. 

The  cost  of  fuel  necessary  to  generate  the  heat  in  the  furnace  is  a matter  of  considerable  importance 
since  it  is  a perpetual  expense.  It  frequently  occurs  that  extra  money  invested  in  superior  heating 
apparatus  will  be  quickly  offset  by  the  fuel  saved. 

The  kind  of  fuel  used  largely  determines  its  cost  of  course.  Good  anthracite  coal  is  generally  the  best 
and  cheapest  fuel  to  use.  Indeed  bituminous  coal  ought  to  be  very  much  cheaper  to  compensate  for  the 
extra  labor  necessary  in  using  it,  from  the  fact  that  apparatus  for  burning  soft  coal  must  be  cleaned  very 
frequently  to  prevent  the  flue  becoming  choked  with  soot. 


■ • - ■ -I 


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HEAT. 


It  is  not  the  purpose  of  this  articie  to  go  into  any  elaborate  theorizing  as  to  what  heat  is.  Indeed,  we 
would  much  prefer  to  leave  out  theory  altogether,  were  it  not  for  the  fact  that  this  work  is  especially 
addressed  to  those  interested  in  educational  matters,  and  who,  therefore,  wish  to  understand  the  “reason  why” 
for  the  facts  we  set  forth.  W e are  somewhat  diffident  about  telling  all  we  know  on  this  subject,  for  fear  we 
may,  like  some  of  the  “ authorities  ” on  warming  and  ventilation,  inadvertently  expose  how  much  we  do  not 
know.  Leaving  others,  therefore,  to  settle  the  question  of  what  heat  is,  we  propose  to  consider  what  heat 
does,  and  how  it  does  it. 

To  make  as  plain  as  possible  the  different  ways  in  which  substances  receive  heat,  or  the  different  manners 
in  which  heat  spreads  from  a heated  body,  we  have  prepared  plate  K,  above. 

We  represent  here  a metal  globe,  “A,”  through  which  are  passed  a vertical  and  a horizontal  rod  ; on 
these  rods,  equi-distant  from  the  center  of  globe,  small  balls  (B  B B B)  are  placed.  From  the  globe  in  all 
directions,  radial  lines  (c  c c c)  are  shown.  The  cool  air  of  the  room  is  shown  in  the  blue  tint,  and  the  hot 
surfaces  and  warm  air  are  represented  by  the  red  tint. 

CONDUCTION. 

Heat  spreads  through  substances,  from  particle  to  particle,  with  a velocity  proper  to  each  substance. 

Heat  so  diffused,  is  called  conducted  heat.  It  is  by  conduction  that  the  heat  from  the  fire  in  the  stove  or 
furnace,  or,  from  the  steam  or  hot  water  in  the  radiators,  passes  through  the  metal,  and  is  brought  to  the 

outside. 


31 

All  solids  conduct  heat  more  or  less  rapidly  ; the  power  of  conduction  depending  largely  upon  the 
density  of  the  substance  ; thus  silver  conducts  heat  about  five  times  as  well  as  brass,  and  brass  about  twice  as 
rapidly  as  iron.  Many  substances  such  as  fire-brick,  mineral  wool,  asbestos,  etc.,  are  commonly  called  non- 
conductors, and  are  used  to  prevent  the  spread  of  heat  by  conduction,  though  they  too  conduct  heat,  but  in  a 
low  degree. 

Liquids,  because  of  the'  mobility  of  their  particles,  do  not  conduct  heat  readily.  Water  is  an  almost 
absolute  non-conductor  of  heat,  though  if  its  free  movement  be  obstructed  by  anything  like  starch  or  glue 
it  will  conduct  slightly. 

Air  is  probably  the  worst  conductor  of  heat  known  ; that  is,  it  is  the  substance  which  when  at  rest, 
impedes  the  passage  of  heat  most.  The  double  casing  on  a furnace,  or  double  windows  on  dwellings,  are 
examples  of  the  prevention  of  the  loss  of  heat,  by  a thin  layer  of  air. 

Heat  is  diffused  by  conduction  equally  well  in  all  directions.  Referring  to  the  plate,  it  will  be  seen  that 
the  balls  B,  B,  B,  B,  are  heated  by  conduction  equally  from  the  hot  globe  “ A.” 

Radiation. 

Heat  spreads  also  by  being  radiated  or  transferred  from  one  body  to  another  through  transparent  substances 

or  empty  space,  with  a readiness  which  is  governed  by  the  material  and  state  of  the  giving  and 

receiving  surfaces. 

Like  conducted  heat,  radiant  heat  spreads  equally  in  all  directions  and  the  same  law  of  intensity  governs 
both,  viz  : it  decreases  in  intensity  according  to  the  square  of  the  distance  of  heated  solid  ; i.  e.,  at  two 
feet  its  intensity  is  reduced  to  one-fourth,  and  at  three  feet  to  one-ninth,  etc. 

Radiant  heat  possesses  the  property  of  passing  through  many  substances  without  affecting  their  tempera- 
ture. Thus  sufficient  radiant  heat  may  pass  through  and  be  concentrated  by  a lens  made  of  ice  to  ignite 
gunpowder  placed  at  the  focus  of  the  lens,  and  yet  the  ice  is  not  melted,  because  it  has  not  intercepted  and 
absorbed  the  rays  of  heat. 

Many  instances  of  this  property  of  radiant  heat  to  pass  through  solid  substances  might  be  given  but  it 
is  not  necessary  to  do  so  here. 

Liquids  absorb  and  become  warmed  by  radiant  heat  to  some  extent. 

The  effect  of  radiant  heat  upon  air  is  the  point  which  most  concerns  us  practically,  and  we  find  by 
investigation  and  experience,  that  radiant  heat  passes  through  air  without  affecting  its  temperature  at  all , 
if  the  air  be  dry. 

Air,  therefore,  cannot  be  warmed  by  radiation.  This  fact  has  a most  important  bearing  upon  the  con- 
struction of  “ air-warmers  ” or  furnaces,  though  it  is  frequently  overlooked  by  those  who  manufacture  such 
apparatus. 

The  surface  of  a substance  greatly  influences  its  capacity  to  radiate  heat,  or  to  receive  radiated  heat. 
Thus  cast-iron,  if  it  has  a rough  surface  will  quickly  absorb  heat,  while  if  its  surface  be  polished  it  will  reflect 
most  of  the  heat  rays,  instead  of  absorbing  them. 

The  greater  the  capacity  of  a substance  to  radiate  heat,  the  greater  also  its  capacity  for  absording  it  and 
becoming  heated. 

All  bodies  radiate  heat,  whether  they  are  above  or  below  the  temperature  of  the  medium  in  which  they 
are  placed.  Thus,  heat-rays  are  radiated  by  boiling  water,  a red-hot  ball,  or  a cake  of  ice,  and  this  radiation 
goes  on  until  an  equilibrium  of  temperature  is  reached. 


32 


Convection. 

Heat  spreads  in  fluids  by  the  transference  of  their  particles,  or  convection. 

The  term  “convection”  means  carrying  or  transporting.  The  heat  which  is  taken  up  by  the  particles 
of  a fluid,  in  contact  with  the  hot  surface  and  carried  away,  is  called  convected  heat.  This  principle  of 
convection  is  one  not  commonly  understood  by  those  who  construct  and  introduce  warm-air  or  hot-water 
apparatus,  though  it  is  the  foundation  principle  of  their  work. 

It  is  a commonly  accepted  saying,  that  “ heat  rises,”  but  this  is  not  strictly  true.  It  is  not  true  of 
conducted  heat,  nor  of  radiant  heat,  for  they  spread  equally  in  all  directions,  and  it  is  only  true  of  convected 
heat,  to  say  that  it  rises , when  it  is  carried  by  some  substance,  as  air  or  water.  Heat  is  not  a substance.  It 
has  neither  volume  nor  weight,  and  no  existence  separate  from  some  substance,  and  therefore  cannot  be  said 
to  rise  or  fall.  We  call  attention  to  these  points  only  to  bring  out  the  fact,  that  if  heat  is  to  be  carried,  a 
carrier  is  necessary.  In  the  hot- water  system  the  water  is  the  carrier,  and  as  it  circulates  through  the  boiler 
it  receives  heat,  and  carries  it  to  the  radiators  where  it  is  given  out. 

In  the  warm-air  system  air  is  the  heat  carrier,  taking  up  and  carrying  the  heat  just  as  the  water  does. 

It  is  just  as  sensible  to  expect  to  heat  a building  through  the  pipes  of  the  hot-water  system  if  the  water 
be  not  supplied,  as  to  expect  to  warm  a building  through  warm  air  flues  if  the  air  be  omitted.  The  common 
complaint  in  school  houses  and  churches,  in  fact  in  the  use  of  furnaces  generally,  is  : that  “ though  there  is  a 
hot  fire  and  the  furnace  is  intensely  heated,  yet  the  heat  won't  come  up.” 

It  is  not  our  business  to  point  out  the  remedy  for  this  trouble  just  mentioned,  but  we  will  guarantee  that 
wherever  we  contract  to  heat  a building  with  warm  air,  we  will  furnish  apparatus  which  wiil  automatically 
control  the  air  supply,  and  that  the  heat  will  always  “ come  up.” 

There  is  a general  misuse  of  the  term  “radiation,”  and  a misconception  of  its  meaning.  We  speak  of  a 
steam  “ radiator,”  when  as  a matter  of  fact,  the  principal  work  of  the  “ radiator”  is  done  by  convection  or  the 
taking  up  of  the  heat  by  the  air  which  comes  in  contact  with  the  surface  of  the  “ radiator.” 

The  term  “ Indirect  radiation,”  is  used  to  express,  in  steam  heating,  or  hot-water  heating,  what  is  really 
“ convection,”  and  not  “ radiation  ” at  all.  Heat  is  spoken  of  as  “ radiating  ” through  cast  or  wrought  iron, 
when,  of  course,  it  goes  through  metal  only  by  conduction. 

The  open  fire  place  warms  a room  by  direct  radiant  heat  alone. 

The  ordinary  stove  heats  principally  by  radiation,  and  slightly  by  convection. 

The  “ direct  ” steam  radiator  heats  almost  wholly  by  convection,  and  only  slightly  by  radiation. 

The  indirect  steam  radiator  warms  by  convection  only. 

The  warm  air  furnace  heats  by  convection  only. 

Since  the  fire  place  and  stove  heat  by  radiation,  a room  cannot  be  evenly  warmed  by  them. 

With  the  direct  steam  radiation,  a room  can  be  heated  quite  uniformly,  but  ventilation  is  entirely  lacking. 

With  the  “ indirect  radiation,”  and  the  warm  air  furnace,  an  even  temperature  and  good  ventilation  can 
be  secured. 

The  great  advantage  obtained  at  present  by  indirect  radiation  over  the  common  furnace,  is  in  the 
amount  of  surface  used  to  warm  the  air.  For  instance,  to  warm  a school  house  of,  say,  eight  rooms,  each 
containing  about  8000  cubic  feet,  would  require  not  less  than  1600  square  feet  of  heating  surface  if  in- 
direct steam  radiation  were  used,  while  there  would  not  be  over  200  square  feet  in  the  two  common  furnaces 
which  would  ordinarily  be  used  to  heat  the  64000  cubic  feet  of  space.  This  subject  is  more  fully  consid- 
ered under  the  description  of  our  furnace,  which  is  especially  designed  to  overcome  this  difficulty. 


THE  “MAHONY'S  FAVORITE"  FURNACE, 

of  which  a view  is  shown  on  page  25,  is  constructed  especially  for  the  heavy  work  of  heating  and  ventilating 
public  buildings,  where  a very  large  volume  of  air  has  to  be  warmed,  and  the  apparatus  is  to  be  under  the 
care  of  the  janitor. 

The  average  janitor  is  not  apt  to  be  very  careful  of  the  furnaces  he  cares  for,  and  apparatus  placed  in  his 
charge  needs  to  be  very  heavy  and  strong  if  it  is  to  prove  durable.  The  simple  construction  of  the  Furnace 
renders  it  easy  to  care  for  and  keep  clean.  This  is  a very  important  matter  and  one  frequently  overlooked. 
The  strongest  guarantee  as  to  heating  and  ventilating  may  be  filled  with  apparatus  which  may  be  neither 
durable  nor  convenient  to  keep  clean  and  in  good  working  order. 

With  ordinary  good  care  our  Furnaces  will  run  for  years  without  the  expenditure  of  a cent  being 
necessary  for  repairs.  A burned  out  grate  can  be  readily  replaced  by  a new  one  without  disturbing  the 
Furnace. 

As  our  Furnace  is  now  constructed,  if  the  proper  supply  of  fresh  air  be  admitted,  it  cannot  be  made  red- 
hot  j the  flame  and  products  of  combustion  being  distributed  over  so  large  a surface  that  the  air  takes  up  the 
heat  as  fast  as  the  burning  fuel  generates  it. 

There  is  considerable  prejudice  at  present  against  furnaces,  which  some  manufacturers  seek  to  avoid  by 
calling  their  furnaces  “air  warmers  but  the  “air  warmer”  is  still  a furnace  and  the  furnace  ought  to  be  an 
“air  warmer.” 

Nearly  all  the  furnaces  on  the  market  are  built  on  the  same  general  plan  ; being  designed  to  heat  a small 
volume  of  air  very  hot.  Our  whole  aim  is  to  produce  a furnace  which  will  heat  as  large  a volume  of  air  as 
possible  to  a temperature  of  not  over  150°  F.  With  the  common  furnace  it  requires  many  hours  to  heat  the 
lower  part  of  a church  though  the  temperature  at  the  ceiling  may  be  very  high.  We  have  frequently  found  a 
difference  of  over  ioo°  F.  between  the  temperature  at  the  ceiling  and  three  feet  from  the  floor  after  common 
furnaces  had  been  running  for  hours,  while  with  our  system  we  can  heat  the  building  in  the  coldest  weather 
in  from  three  to  six  hours  and  not  have  a difference  in  temperature  of  over  io°  F.  between  ceiling  and  floor. 


THE  COMBINATION  HEATER, 

of  which  we  show  a cut  on  page  27,  is  the  most  powerful  and  economical  apparatus  yet  placed  before  the  public. 
The  idea  of  combining  in  one  heater  a warm  air  furnace  and  a steam  or  hot  water  boiler,  is  not  new,  but  all 
efforts  to  produce  such  a combination  heretofore  have  resulted  in  a very  complicated  and  expensive,  though 
successful  apparatus. 

It  will  be  seen  at  a glance  how  simple  and  free  from  joints  is  the  heater  we  produce.  The  boiler  consists 
of  the  fire  pot  of  the  Furnace,  which  is  hollow  and  cast  in  one  piece,  and  an  upper  section  also  in  one  piece, 
the  two  being  connected  by  several  pipes  having  “right”  and  “left”  threads.  The  fire  pot  being  always 
filled  with  water,  is  practically  indestructible  since  it  can  never  become  red-hot.  The  whole  boiler  is  enclosed 
in  a steel  plate  or  wrought  iron  drum  which  forms  the  heating  surface  of  the  Furnace.  The  full  arrows  show 
the  direction  of  the  currents  of  warm  air  and  products  of  combustion,  and  the  half  arrows  the  direction  of 
the  currents  of  water  through  the  boiler.  There  is  not  a packed  joint  in  the  boiler , and  the  Furnace  is 
warranted  gas-tight. 


34 


Careful  experiments  show  that  with  the  strongest  fire  we  succeed  in  reducing  the  temperature  of  the- 
smoke  flue  to  the  lowest  limit  consistent  with  a good  draft.  The  same  fire  and  the  same  amount  of  fuel  will, 
do  much  more  work  in  the  Furnace  and  Boiler  combined  than  in  either  used  separately. 

This  Combination  is  much  better  for  schools  and  churches  than  either  steam  or  hot  water — costs  less  to- 
introduce,  and  much  less  to  maintain.  The  heating  being  done  by  the  Boiler  and  the  ventilating  by  the 
Furnace. 


Our  Guarantee. 

Whenever  we  make  contracts  for  warming  and  ventilating  buildings  ; the  parties  with  whom  we  contract 
are  at  liberty  to  have  an  agreement  drawn  up  by  any  one  they  may  choose,  covering  the  points  of  the  contract. 
If  that  is  not  done  we  give  a guarantee  as  follows  : 

“We  hereby  guarantee  that  the  apparatus  furnished  for  warming  and  ventilating  the 

located  in has  sufficient  capacity  to,  and  will,  with  ordinary  good  care  and  proper  attention  to 

fires,  regulation  of  drafts,  fresh  air  supply,  etc.,  heat  said  building,  or  such  parts  thereof  as  contract  covers,  to  a temperature  of  70° 

Fah.  in  any  weather,  and  ventilate  the  building  to  the  extent  that  the  air  shall  be  changed  as  often  as times  per  hour.  The 

temperature  in  all  parts  of  each  room  shall  be  uniform  at  the  same  height  from  floor,  and  all  parts  of  building,  covered  by  the 
contract  shall  be  warmed  and  ventilated  at  the  same  time,  unless  otherwise  expressly  agreed. 

If,  after  proper  tests,  the  apparatus  furnished  cannot  be  made  to  .secure  the  results  guaranteed,  we  agree  to  refund  the  money 
received  for  same,  remove  the  apparatus  from  the  building  and  repair  all  damage  to  building  caused  by  the  introduction  and  removal 
of  our  apparatus.” 


To  Boards  of  Education. 

If  for  any  reason  you  are  considering  the  subject  of  warming  and  ventilating  your  school  houses,  whether 
new  or  old  buildings,  it  will  benefit  you  to  correspond  with  us  before  coming  to  a decision  as  to  the  methods 
and  apparatus  you  will  use. 

No  part  of  your  work  is  so  important  as  providing  comfortable  and  healthful  school  buildings,  but  with- 
out a successful  system  of  warming  and  ventilation,  the  finest  school  house  is  simply  an  exhibition  of  folly. 

Remember  this : We  will  make  a contract  with  you  to  secure  the  results  you  want  in  such  a manner 
that  even  if  we  were  to  fail  entirely  to  fill  our  guarantee,  there  could  be  no  loss  or  damage  to  you.  Hoping 
that  this  work  has  sufficiently  interested  you  to  induce  you  to  correspond  with  us,  we  are 

Very  Truly  Yours, 

The  Mahony  Warming  and  Ventilating  Establishment. 


Troy,  X . Y. 


